In the field of passenger or freight transportation, particularly in the field of aeronautics, vehicle manufacturers are trying to reduce the weight of the vehicles, while making them highly resistant. To do so, they are trying to replace the metal structure of the vehicles, at least in part, with a light or lighter structure.
Particularly in the field of aeronautics, the aircraft structure is generally made from metal panels, assembled with fastening systems that are also metal. In particular, the floors of the aircraft are made of a horizontal metal structure attached to a vertical frame structure that is also metal. The horizontal structure is generally composed of metal spars and cross beams, made of aluminum or other alloys, for example. This horizontal structure is attached to the metal frames placed on either side of the aircraft fuselage that comprise the frame structure of the aircraft.
In the case of passenger transportation, the horizontal structure also includes rails for the seats or other cabin fixtures. The rails are metal, and the passenger seats and most cabin fixtures are attached to them, specifically for transporting freight or passengers, like galleys, toilets, partitions, etc. These rails are perpendicular to the cross beams. They either placed on the cross beams, or across them. In aircraft used to transport passengers, at least two rails are mounted in the floor, spaced apart and running longitudinally from the front of the aircraft to the back. Chassis, each of which has two or more seats, are attached to these rails to form a bay of armchairs. Other elements of the cabin fixtures are attached to these same rails.
The horizontal structure made in this way is covered with floor panels placed on the rails. In effect, the unit made up of the rails and cross beams is an approximately plane but not uniform surface. Floor panels are therefore necessary to make this surface continuous and uniform, in order to ensure the safety of the passengers and crew when they move around onboard the aircraft.
Such floors are relatively cumbersome due to the fact that the different elements of which they are composed are superimposed on top of one another. Also, with such floors, the position of the rails is not very flexible: the rails are placed in the floor and can no longer be moved without totally changing the floor.
Moreover, to best preserve the volume of the passenger cabin and that of the cargo compartment, the different wires in the aircraft (electric cables, hydraulic hoses, air conditioning pipes and other means of transferring energy) are installed in the interior of the cross beams. In other words, a large part, or even all of the electric wiring runs inside the cross beams in the floor of the aircraft to limit the space necessary for them to go through. Now, the fact that this wiring is placed inside the cross beams makes it hard to install, on one hand, and delicate to replace, on the other. Indeed, in a traditional metal structure, to replace the wiring it is necessary to take the floor apart, at least partly, to remove the existing wiring and then replace it with the new, which must be passed through different cross beams.
In general, aircraft with metal structures have the disadvantage of being heavy. To reduce the structural weight of the aircraft, aeronautics manufacturers are trying to replace certain metal elements with elements made of composite material. Indeed, since composite materials have the advantage of being relatively light compared to metal, the total weight of an aircraft with a composite structure is significantly lighter than that of an aircraft with a metal structure.
It is therefore conceivable to replace the current metal floors with floors made of composite materials with the same structure. However, even if such floors made it possible to save weight, they would not make it possible to fix the disadvantages of the current floors described above (cumbersome, inflexible rail position, hard to install and replace wiring).